10 Cool Things About Carl Sagan

This sheet of paper is part of the Carl Sagan and Ann Druyan Archives, housed at the Library of Congress in Washington, D.C. Paul Morigi/Getty Images

On Nov. 9, 1994, Carl Sagan turned 60 and his friends in the Cornell Astronomy Department hosted a party in his honor. There were speeches by loved ones, colleagues and former students, and letters from people like Arthur C. Clarke and Al Gore.

The highlight, however, was a surprise announcement by Eleanor Helin, who was an expert at discovering asteroids: Her most recent finding, asteroid 4970, had been named "Asteroid Druyan."

The asteroid, named after Sagan's wife, Ann Druyan, was locked in an eternal orbit with another notable heavenly body: "Asteroid 2709 Sagan," the asteroid earlier named after Sagan [source: Spangenburg]. This was a wonderful birthday present and expression of love.

On a more humorous note, scientists have paid tribute to Sagan's deathless phrase "billions and billions," by naming a unit of measurement after him. The sagan is a number equal to at least 4 billion [source: Know Your Meme].